1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 //-----------------------------------------------------------------------------
21 // Reconstructed track in ALICE dimuon spectrometer
22 //-----------------------------------------------------------------------------
24 #include "AliMUONTrack.h"
26 #include "AliMUONReconstructor.h"
27 #include "AliMUONRecoParam.h"
28 #include "AliMUONVCluster.h"
29 #include "AliMUONVClusterStore.h"
30 #include "AliMUONObjectPair.h"
31 #include "AliMUONConstants.h"
32 #include "AliMUONTrackExtrap.h"
39 #include <Riostream.h>
42 ClassImp(AliMUONTrack) // Class implementation in ROOT context
45 //__________________________________________________________________________
46 AliMUONTrack::AliMUONTrack()
48 fTrackParamAtCluster(0x0),
49 fFitWithVertex(kFALSE),
52 fClusterWeightsNonBending(0x0),
53 fClusterWeightsBending(0x0),
58 fChi2MatchTrigger(0.),
60 fTrackParamAtVertex(0x0),
61 fHitsPatternInTrigCh(0),
64 /// Default constructor
65 fVertexErrXY2[0] = 0.;
66 fVertexErrXY2[1] = 0.;
69 //__________________________________________________________________________
70 AliMUONTrack::AliMUONTrack(AliMUONObjectPair *segment)
72 fTrackParamAtCluster(new TClonesArray("AliMUONTrackParam",10)),
73 fFitWithVertex(kFALSE),
76 fClusterWeightsNonBending(0x0),
77 fClusterWeightsBending(0x0),
82 fChi2MatchTrigger(0.),
84 fTrackParamAtVertex(0x0),
85 fHitsPatternInTrigCh(0),
88 /// Constructor from two clusters
90 fVertexErrXY2[0] = 0.;
91 fVertexErrXY2[1] = 0.;
93 // Pointers to clusters from the segment
94 AliMUONVCluster* firstCluster = (AliMUONVCluster*) segment->First();
95 AliMUONVCluster* lastCluster = (AliMUONVCluster*) segment->Second();
97 // Compute track parameters
98 Double_t z1 = firstCluster->GetZ();
99 Double_t z2 = lastCluster->GetZ();
100 Double_t dZ = z1 - z2;
102 Double_t nonBendingCoor1 = firstCluster->GetX();
103 Double_t nonBendingCoor2 = lastCluster->GetX();
104 Double_t nonBendingSlope = (nonBendingCoor1 - nonBendingCoor2) / dZ;
106 Double_t bendingCoor1 = firstCluster->GetY();
107 Double_t bendingCoor2 = lastCluster->GetY();
108 Double_t bendingSlope = (bendingCoor1 - bendingCoor2) / dZ;
109 // Inverse bending momentum
110 Double_t bendingImpact = bendingCoor1 - z1 * bendingSlope;
111 Double_t inverseBendingMomentum = 1. / AliMUONTrackExtrap::GetBendingMomentumFromImpactParam(bendingImpact);
113 // Set track parameters at first cluster
114 AliMUONTrackParam trackParamAtFirstCluster;
115 trackParamAtFirstCluster.SetZ(z1);
116 trackParamAtFirstCluster.SetNonBendingCoor(nonBendingCoor1);
117 trackParamAtFirstCluster.SetNonBendingSlope(nonBendingSlope);
118 trackParamAtFirstCluster.SetBendingCoor(bendingCoor1);
119 trackParamAtFirstCluster.SetBendingSlope(bendingSlope);
120 trackParamAtFirstCluster.SetInverseBendingMomentum(inverseBendingMomentum);
122 // Set track parameters at last cluster
123 AliMUONTrackParam trackParamAtLastCluster;
124 trackParamAtLastCluster.SetZ(z2);
125 trackParamAtLastCluster.SetNonBendingCoor(nonBendingCoor2);
126 trackParamAtLastCluster.SetNonBendingSlope(nonBendingSlope);
127 trackParamAtLastCluster.SetBendingCoor(bendingCoor2);
128 trackParamAtLastCluster.SetBendingSlope(bendingSlope);
129 trackParamAtLastCluster.SetInverseBendingMomentum(inverseBendingMomentum);
131 // Compute and set track parameters covariances at first cluster
132 TMatrixD paramCov(5,5);
135 paramCov(0,0) = firstCluster->GetErrX2();
136 paramCov(0,1) = firstCluster->GetErrX2() / dZ;
137 paramCov(1,0) = paramCov(0,1);
138 paramCov(1,1) = ( firstCluster->GetErrX2() + lastCluster->GetErrX2() ) / dZ / dZ;
140 paramCov(2,2) = firstCluster->GetErrY2();
141 paramCov(2,3) = firstCluster->GetErrY2() / dZ;
142 paramCov(3,2) = paramCov(2,3);
143 paramCov(3,3) = ( firstCluster->GetErrY2() + lastCluster->GetErrY2() ) / dZ / dZ;
144 // Inverse bending momentum (vertex resolution + bending slope resolution + 10% error on dipole parameters+field)
145 paramCov(4,4) = ((AliMUONReconstructor::GetRecoParam()->GetBendingVertexDispersion() *
146 AliMUONReconstructor::GetRecoParam()->GetBendingVertexDispersion() +
147 (z1 * z1 * lastCluster->GetErrY2() + z2 * z2 * firstCluster->GetErrY2()) / dZ / dZ) /
148 bendingImpact / bendingImpact + 0.1 * 0.1) * inverseBendingMomentum * inverseBendingMomentum;
149 paramCov(2,4) = - z2 * firstCluster->GetErrY2() * inverseBendingMomentum / bendingImpact / dZ;
150 paramCov(4,2) = paramCov(2,4);
151 paramCov(3,4) = - (z1 * lastCluster->GetErrY2() + z2 * firstCluster->GetErrY2()) * inverseBendingMomentum / bendingImpact / dZ / dZ;
152 paramCov(4,3) = paramCov(3,4);
155 trackParamAtFirstCluster.SetCovariances(paramCov);
157 // Compute and set track parameters covariances at last cluster
158 paramCov(1,0) = - paramCov(1,0);
159 paramCov(0,1) = - paramCov(0,1);
160 paramCov(3,2) = - paramCov(3,2);
161 paramCov(2,3) = - paramCov(2,3);
162 paramCov(2,4) = z1 * lastCluster->GetErrY2() * inverseBendingMomentum / bendingImpact / dZ;
163 paramCov(4,2) = paramCov(2,4);
164 trackParamAtLastCluster.SetCovariances(paramCov);
166 // Add track parameters at clusters
167 AddTrackParamAtCluster(trackParamAtFirstCluster,*firstCluster);
168 AddTrackParamAtCluster(trackParamAtLastCluster,*lastCluster);
172 //__________________________________________________________________________
173 AliMUONTrack::AliMUONTrack(const AliMUONTrack& track)
175 fTrackParamAtCluster(0x0),
176 fFitWithVertex(track.fFitWithVertex),
178 fFitWithMCS(track.fFitWithMCS),
179 fClusterWeightsNonBending(0x0),
180 fClusterWeightsBending(0x0),
181 fGlobalChi2(track.fGlobalChi2),
182 fImproved(track.fImproved),
183 fMatchTrigger(track.fMatchTrigger),
184 floTrgNum(track.floTrgNum),
185 fChi2MatchTrigger(track.fChi2MatchTrigger),
186 fTrackID(track.fTrackID),
187 fTrackParamAtVertex(0x0),
188 fHitsPatternInTrigCh(track.fHitsPatternInTrigCh),
189 fLocalTrigger(track.fLocalTrigger)
193 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
194 if (track.fTrackParamAtCluster) {
195 fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
196 AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->First();
197 while (trackParamAtCluster) {
198 new ((*fTrackParamAtCluster)[GetNClusters()]) AliMUONTrackParam(*trackParamAtCluster);
199 trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->After(trackParamAtCluster);
203 // copy vertex resolution square used during the tracking procedure
204 fVertexErrXY2[0] = track.fVertexErrXY2[0];
205 fVertexErrXY2[1] = track.fVertexErrXY2[1];
207 // copy cluster weights matrices if any
208 if (track.fClusterWeightsNonBending) fClusterWeightsNonBending = new TMatrixD(*(track.fClusterWeightsNonBending));
209 if (track.fClusterWeightsBending) fClusterWeightsBending = new TMatrixD(*(track.fClusterWeightsBending));
211 // copy track parameters at vertex if any
212 if (track.fTrackParamAtVertex) fTrackParamAtVertex = new AliMUONTrackParam(*(track.fTrackParamAtVertex));
216 //__________________________________________________________________________
217 AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& track)
219 /// Asignment operator
220 // check assignement to self
224 // base class assignement
225 TObject::operator=(track);
230 // necessary to make a copy of the objects and not only the pointers in TClonesArray
231 if (track.fTrackParamAtCluster) {
232 fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
233 AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->First();
234 while (trackParamAtCluster) {
235 new ((*fTrackParamAtCluster)[GetNClusters()]) AliMUONTrackParam(*trackParamAtCluster);
236 trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->After(trackParamAtCluster);
240 // copy cluster weights matrix if any
241 if (track.fClusterWeightsNonBending) {
242 if (fClusterWeightsNonBending) {
243 fClusterWeightsNonBending->ResizeTo(*(track.fClusterWeightsNonBending));
244 *fClusterWeightsNonBending = *(track.fClusterWeightsNonBending);
245 } else fClusterWeightsNonBending = new TMatrixD(*(track.fClusterWeightsNonBending));
248 // copy cluster weights matrix if any
249 if (track.fClusterWeightsBending) {
250 if (fClusterWeightsBending) {
251 fClusterWeightsBending->ResizeTo(*(track.fClusterWeightsBending));
252 *fClusterWeightsBending = *(track.fClusterWeightsBending);
253 } else fClusterWeightsBending = new TMatrixD(*(track.fClusterWeightsBending));
256 // copy track parameters at vertex if any
257 if (track.fTrackParamAtVertex) {
258 if (fTrackParamAtVertex) *fTrackParamAtVertex = *(track.fTrackParamAtVertex);
259 else fTrackParamAtVertex = new AliMUONTrackParam(*(track.fTrackParamAtVertex));
262 fFitWithVertex = track.fFitWithVertex;
263 fVertexErrXY2[0] = track.fVertexErrXY2[0];
264 fVertexErrXY2[1] = track.fVertexErrXY2[1];
265 fFitWithMCS = track.fFitWithMCS;
266 fGlobalChi2 = track.fGlobalChi2;
267 fImproved = track.fImproved;
268 fMatchTrigger = track.fMatchTrigger;
269 floTrgNum = track.floTrgNum;
270 fChi2MatchTrigger = track.fChi2MatchTrigger;
271 fTrackID = track.fTrackID;
272 fHitsPatternInTrigCh = track.fHitsPatternInTrigCh;
273 fLocalTrigger = track.fLocalTrigger;
278 //__________________________________________________________________________
279 AliMUONTrack::~AliMUONTrack()
282 delete fTrackParamAtCluster;
283 delete fClusterWeightsNonBending;
284 delete fClusterWeightsBending;
285 delete fTrackParamAtVertex;
288 //__________________________________________________________________________
289 void AliMUONTrack::Clear(Option_t* opt)
292 if (opt && opt[0] == 'C' && fTrackParamAtCluster) fTrackParamAtCluster->Clear("C");
294 delete fTrackParamAtCluster;
295 fTrackParamAtCluster = 0x0;
297 delete fClusterWeightsNonBending; fClusterWeightsNonBending = 0x0;
298 delete fClusterWeightsBending; fClusterWeightsBending = 0x0;
299 delete fTrackParamAtVertex; fTrackParamAtVertex = 0x0;
302 //__________________________________________________________________________
303 TClonesArray* AliMUONTrack::GetTrackParamAtCluster() const
305 /// return array of track parameters at cluster (create it if needed)
306 if (!fTrackParamAtCluster) fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
307 return fTrackParamAtCluster;
310 //__________________________________________________________________________
311 void AliMUONTrack::AddTrackParamAtCluster(const AliMUONTrackParam &trackParam, AliMUONVCluster &cluster, Bool_t copy)
313 /// Copy given track parameters into a new TrackParamAtCluster
314 /// Link parameters with the associated cluster
315 /// If copy=kTRUE: the cluster is copied then passed the trackParam which become its owner
316 /// otherwise: make sure to do not delete the cluster until it is used by the track
318 // check chamber ID of the associated cluster
319 if (cluster.GetChamberId() < 0 || cluster.GetChamberId() > AliMUONConstants::NTrackingCh()) {
320 AliError(Form("Chamber ID of the associated cluster is not valid (ChamberId=%d)",cluster.GetChamberId()));
324 // check whether track parameters are given at the correct cluster z position
325 if (cluster.GetZ() != trackParam.GetZ()) {
326 AliError("track parameters are given at a different z position than the one of the associated cluster");
330 // add parameters to the array of track parameters
331 if (!fTrackParamAtCluster) fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
332 AliMUONTrackParam* trackParamAtCluster = new ((*fTrackParamAtCluster)[GetNClusters()]) AliMUONTrackParam(trackParam);
334 // link parameters with the associated cluster or its copy
336 AliMUONVCluster *clusterCopy = static_cast<AliMUONVCluster*>(cluster.Clone());
337 trackParamAtCluster->SetClusterPtr(clusterCopy, kTRUE);
338 } else trackParamAtCluster->SetClusterPtr(&cluster);
340 // sort the array of track parameters
341 fTrackParamAtCluster->Sort();
344 //__________________________________________________________________________
345 void AliMUONTrack::RemoveTrackParamAtCluster(AliMUONTrackParam *trackParam)
347 /// Remove trackParam from the array of TrackParamAtCluster
348 if (!fTrackParamAtCluster || !fTrackParamAtCluster->Remove(trackParam)) {
349 AliWarning("object to remove does not exist in array fTrackParamAtCluster");
353 fTrackParamAtCluster->Compress();
356 //__________________________________________________________________________
357 void AliMUONTrack::UpdateTrackParamAtCluster()
359 /// Update track parameters at each attached cluster
361 if (GetNClusters() == 0) {
362 AliWarning("no cluster attached to the track");
366 AliMUONTrackParam* startingTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->First();
367 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(startingTrackParam);
368 while (trackParamAtCluster) {
370 // reset track parameters and their covariances
371 trackParamAtCluster->SetParameters(startingTrackParam->GetParameters());
372 trackParamAtCluster->SetZ(startingTrackParam->GetZ());
374 // extrapolation to the given z
375 AliMUONTrackExtrap::ExtrapToZ(trackParamAtCluster, trackParamAtCluster->GetClusterPtr()->GetZ());
378 startingTrackParam = trackParamAtCluster;
379 trackParamAtCluster = (AliMUONTrackParam*) (fTrackParamAtCluster->After(trackParamAtCluster));
384 //__________________________________________________________________________
385 void AliMUONTrack::UpdateCovTrackParamAtCluster()
387 /// Update track parameters and their covariances at each attached cluster
388 /// Include effects of multiple scattering in chambers
390 if (GetNClusters() == 0) {
391 AliWarning("no cluster attached to the track");
395 AliMUONTrackParam* startingTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->First();
396 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(startingTrackParam);
397 Int_t expectedChamber = startingTrackParam->GetClusterPtr()->GetChamberId() + 1;
398 Int_t currentChamber;
399 while (trackParamAtCluster) {
401 // reset track parameters and their covariances
402 trackParamAtCluster->SetParameters(startingTrackParam->GetParameters());
403 trackParamAtCluster->SetZ(startingTrackParam->GetZ());
404 trackParamAtCluster->SetCovariances(startingTrackParam->GetCovariances());
407 AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(),1.);
409 // add MCS in missing chambers if any
410 currentChamber = trackParamAtCluster->GetClusterPtr()->GetChamberId();
411 while (currentChamber > expectedChamber) {
412 // extrapolation to the missing chamber
413 AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, AliMUONConstants::DefaultChamberZ(expectedChamber));
415 AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(),1.);
419 // extrapolation to the z of the current cluster
420 AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, trackParamAtCluster->GetClusterPtr()->GetZ());
423 expectedChamber = currentChamber + 1;
424 startingTrackParam = trackParamAtCluster;
425 trackParamAtCluster = (AliMUONTrackParam*) (fTrackParamAtCluster->After(trackParamAtCluster));
430 //__________________________________________________________________________
431 Bool_t AliMUONTrack::IsValid()
433 /// check the validity of the current track (at least one cluster per requested station)
435 Int_t nClusters = GetNClusters();
436 AliMUONTrackParam *trackParam;
437 Int_t currentStation = 0, expectedStation = 0;
439 for (Int_t i = 0; i < nClusters; i++) {
440 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
442 // skip unrequested stations
443 while (expectedStation < AliMUONConstants::NTrackingSt() &&
444 !AliMUONReconstructor::GetRecoParam()->RequestStation(expectedStation)) expectedStation++;
446 currentStation = trackParam->GetClusterPtr()->GetChamberId()/2;
449 if (currentStation > expectedStation) return kFALSE;
451 // found station --> look for next one
452 if (currentStation == expectedStation) expectedStation++;
456 return expectedStation == AliMUONConstants::NTrackingSt();
460 //__________________________________________________________________________
461 void AliMUONTrack::TagRemovableClusters() {
462 /// Identify clusters that can be removed from the track,
463 /// with the only requirement to have at least 1 cluster per requested station
465 Int_t nClusters = GetNClusters();
466 AliMUONTrackParam *trackParam, *nextTrackParam;
467 Int_t currentCh, nextCh;
469 // reset flags to kFALSE for all clusters in required station
470 for (Int_t i = 0; i < nClusters; i++) {
471 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
472 if (AliMUONReconstructor::GetRecoParam()->RequestStation(trackParam->GetClusterPtr()->GetChamberId()/2))
473 trackParam->SetRemovable(kFALSE);
474 else trackParam->SetRemovable(kTRUE);
477 // loop over track parameters
478 for (Int_t i = 0; i < nClusters; i++) {
479 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
481 currentCh = trackParam->GetClusterPtr()->GetChamberId();
483 // loop over next track parameters
484 for (Int_t j = i+1; j < nClusters; j++) {
485 nextTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(j);
487 nextCh = nextTrackParam->GetClusterPtr()->GetChamberId();
489 // check if the 2 clusters are on the same station
490 if (nextCh/2 != currentCh/2) break;
492 // set clusters in the same station as being removable
493 trackParam->SetRemovable(kTRUE);
494 nextTrackParam->SetRemovable(kTRUE);
502 //__________________________________________________________________________
503 Bool_t AliMUONTrack::ComputeLocalChi2(Bool_t accountForMCS)
505 /// Compute each cluster contribution to the chi2 of the track
506 /// accounting for multiple scattering or not according to the flag
507 /// - Also recompute the weight matrices of the attached clusters if accountForMCS=kTRUE
508 /// - Assume that track parameters at each cluster are corrects
509 /// - Return kFALSE if computation failed
510 AliDebug(1,"Enter ComputeLocalChi2");
512 if (!fTrackParamAtCluster) {
513 AliWarning("no cluster attached to this track");
517 if (accountForMCS) { // Compute local chi2 taking into account multiple scattering effects
519 // Compute MCS covariance matrix only once
520 Int_t nClusters = GetNClusters();
521 TMatrixD mcsCovariances(nClusters,nClusters);
522 ComputeMCSCovariances(mcsCovariances);
524 // Make sure cluster weights are consistent with following calculations
525 if (!ComputeClusterWeights(&mcsCovariances)) {
526 AliWarning("cannot take into account the multiple scattering effects");
527 return ComputeLocalChi2(kFALSE);
530 // Compute chi2 of the track
531 Double_t globalChi2 = ComputeGlobalChi2(kTRUE);
532 if (globalChi2 < 0.) return kFALSE;
534 // Loop over removable clusters and compute their local chi2
535 AliMUONTrackParam* trackParamAtCluster1;
536 AliMUONVCluster *cluster, *discardedCluster;
537 Int_t iCluster1, iCluster2, iCurrentCluster1, iCurrentCluster2;
538 TMatrixD clusterWeightsNB(nClusters-1,nClusters-1);
539 TMatrixD clusterWeightsB(nClusters-1,nClusters-1);
540 Double_t *dX = new Double_t[nClusters-1];
541 Double_t *dY = new Double_t[nClusters-1];
542 Double_t globalChi2b;
543 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->First();
544 while (trackParamAtCluster) {
546 discardedCluster = trackParamAtCluster->GetClusterPtr();
548 // Recompute cluster weights without the current cluster
549 if (!ComputeClusterWeights(clusterWeightsNB, clusterWeightsB, &mcsCovariances, discardedCluster)) {
550 AliWarning("cannot take into account the multiple scattering effects");
553 return ComputeLocalChi2(kFALSE);
556 // Compute track chi2 without the current cluster
558 iCurrentCluster1 = 0;
559 for (iCluster1 = 0; iCluster1 < nClusters ; iCluster1++) {
560 trackParamAtCluster1 = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1);
561 cluster = trackParamAtCluster1->GetClusterPtr();
563 if (cluster == discardedCluster) continue;
565 // Compute and save residuals
566 dX[iCurrentCluster1] = cluster->GetX() - trackParamAtCluster1->GetNonBendingCoor();
567 dY[iCurrentCluster1] = cluster->GetY() - trackParamAtCluster1->GetBendingCoor();
569 iCurrentCluster2 = 0;
570 for (iCluster2 = 0; iCluster2 < iCluster1; iCluster2++) {
571 cluster = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster2))->GetClusterPtr();
573 if (cluster == discardedCluster) continue;
575 // Add contribution from covariances
576 globalChi2b += (clusterWeightsNB(iCurrentCluster1, iCurrentCluster2) +
577 clusterWeightsNB(iCurrentCluster2, iCurrentCluster1)) * dX[iCurrentCluster1] * dX[iCurrentCluster2] +
578 (clusterWeightsB(iCurrentCluster1, iCurrentCluster2) +
579 clusterWeightsB(iCurrentCluster2, iCurrentCluster1)) * dY[iCurrentCluster1] * dY[iCurrentCluster2];
584 // Add contribution from variances
585 globalChi2b += clusterWeightsNB(iCurrentCluster1, iCurrentCluster1) * dX[iCurrentCluster1] * dX[iCurrentCluster1] +
586 clusterWeightsB(iCurrentCluster1, iCurrentCluster1) * dY[iCurrentCluster1] * dY[iCurrentCluster1];
592 trackParamAtCluster->SetLocalChi2(globalChi2 - globalChi2b);
594 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(trackParamAtCluster);
600 } else { // without multiple scattering effects
602 AliMUONVCluster *discardedCluster;
604 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->First();
605 while (trackParamAtCluster) {
607 discardedCluster = trackParamAtCluster->GetClusterPtr();
610 dX = discardedCluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
611 dY = discardedCluster->GetY() - trackParamAtCluster->GetBendingCoor();
614 trackParamAtCluster->SetLocalChi2(dX * dX / discardedCluster->GetErrX2() + dY * dY / discardedCluster->GetErrY2());
616 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(trackParamAtCluster);
625 //__________________________________________________________________________
626 Double_t AliMUONTrack::ComputeGlobalChi2(Bool_t accountForMCS)
628 /// Compute the chi2 of the track accounting for multiple scattering or not according to the flag
629 /// - Assume that track parameters at each cluster are corrects
630 /// - Assume the cluster weights matrices are corrects
631 /// - Return negative value if chi2 computation failed
632 AliDebug(1,"Enter ComputeGlobalChi2");
634 if (!fTrackParamAtCluster) {
635 AliWarning("no cluster attached to this track");
643 // Check the weight matrices. If weight matrices are not available compute chi2 without MCS
644 if (!fClusterWeightsNonBending || !fClusterWeightsBending) {
645 AliWarning("cluster weights including multiple scattering effects are not available\n\t\t --> compute chi2 WITHOUT multiple scattering");
646 return ComputeGlobalChi2(kFALSE);
648 Int_t nClusters = GetNClusters();
649 if (fClusterWeightsNonBending->GetNrows() != nClusters || fClusterWeightsBending->GetNcols() != nClusters) {
650 AliWarning("cluster weights including multiple scattering effects are not available\n\t\t --> compute chi2 WITHOUT multiple scattering");
651 return ComputeGlobalChi2(kFALSE);
655 AliMUONVCluster *cluster;
656 Double_t *dX = new Double_t[nClusters];
657 Double_t *dY = new Double_t[nClusters];
658 AliMUONTrackParam* trackParamAtCluster;
659 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
660 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1);
661 cluster = trackParamAtCluster->GetClusterPtr();
662 dX[iCluster1] = cluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
663 dY[iCluster1] = cluster->GetY() - trackParamAtCluster->GetBendingCoor();
664 for (Int_t iCluster2 = 0; iCluster2 < iCluster1; iCluster2++) {
665 chi2 += ((*fClusterWeightsNonBending)(iCluster1, iCluster2) + (*fClusterWeightsNonBending)(iCluster2, iCluster1)) * dX[iCluster1] * dX[iCluster2] +
666 ((*fClusterWeightsBending)(iCluster1, iCluster2) + (*fClusterWeightsBending)(iCluster2, iCluster1)) * dY[iCluster1] * dY[iCluster2];
668 chi2 += ((*fClusterWeightsNonBending)(iCluster1, iCluster1) * dX[iCluster1] * dX[iCluster1]) +
669 ((*fClusterWeightsBending)(iCluster1, iCluster1) * dY[iCluster1] * dY[iCluster1]);
676 AliMUONVCluster *cluster;
678 AliMUONTrackParam* trackParamAtCluster;
679 Int_t nClusters = GetNClusters();
680 for (Int_t iCluster = 0; iCluster < nClusters ; iCluster++) {
681 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster);
682 cluster = trackParamAtCluster->GetClusterPtr();
683 dX = cluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
684 dY = cluster->GetY() - trackParamAtCluster->GetBendingCoor();
685 chi2 += dX * dX / cluster->GetErrX2() + dY * dY / cluster->GetErrY2();
694 //__________________________________________________________________________
695 Bool_t AliMUONTrack::ComputeClusterWeights(TMatrixD* mcsCovariances)
697 /// Compute the weight matrices of the attached clusters, in non bending and bending direction,
698 /// accounting for multiple scattering correlations and cluster resolution
699 /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
700 /// - Assume that track parameters at each cluster are corrects
701 /// - Return kFALSE if computation failed
702 AliDebug(1,"Enter ComputeClusterWeights1");
704 if (!fTrackParamAtCluster) {
705 AliWarning("no cluster attached to this track");
710 Int_t nClusters = GetNClusters();
711 if (!fClusterWeightsNonBending) fClusterWeightsNonBending = new TMatrixD(nClusters,nClusters);
712 if (!fClusterWeightsBending) fClusterWeightsBending = new TMatrixD(nClusters,nClusters);
714 // Compute weights matrices
715 if (!ComputeClusterWeights(*fClusterWeightsNonBending, *fClusterWeightsBending, mcsCovariances)) return kFALSE;
721 //__________________________________________________________________________
722 Bool_t AliMUONTrack::ComputeClusterWeights(TMatrixD& clusterWeightsNB, TMatrixD& clusterWeightsB,
723 TMatrixD* mcsCovariances, AliMUONVCluster* discardedCluster) const
725 /// Compute the weight matrices, in non bending and bending direction,
726 /// of the other attached clusters assuming the discarded one does not exist
727 /// accounting for multiple scattering correlations and cluster resolution
728 /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
729 /// - Return kFALSE if computation failed
730 AliDebug(1,"Enter ComputeClusterWeights2");
732 // Check MCS covariance matrix and recompute it if need
733 Int_t nClusters = GetNClusters();
734 Bool_t deleteMCSCov = kFALSE;
735 if (!mcsCovariances) {
736 mcsCovariances = new TMatrixD(nClusters,nClusters);
737 deleteMCSCov = kTRUE;
738 ComputeMCSCovariances(*mcsCovariances);
741 // Resize the weights matrices; alocate memory
742 if (discardedCluster) {
743 clusterWeightsNB.ResizeTo(nClusters-1,nClusters-1);
744 clusterWeightsB.ResizeTo(nClusters-1,nClusters-1);
746 clusterWeightsNB.ResizeTo(nClusters,nClusters);
747 clusterWeightsB.ResizeTo(nClusters,nClusters);
751 AliMUONVCluster *cluster1, *cluster2;
752 Int_t iCurrentCluster1, iCurrentCluster2;
754 // Compute the covariance matrices
755 iCurrentCluster1 = 0;
756 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
757 cluster1 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1))->GetClusterPtr();
759 if (cluster1 == discardedCluster) continue;
761 // Loop over next clusters
762 iCurrentCluster2 = iCurrentCluster1;
763 for (Int_t iCluster2 = iCluster1; iCluster2 < nClusters; iCluster2++) {
764 cluster2 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster2))->GetClusterPtr();
766 if (cluster2 == discardedCluster) continue;
768 // Fill with MCS covariances
769 clusterWeightsNB(iCurrentCluster1, iCurrentCluster2) = (*mcsCovariances)(iCluster1,iCluster2);
771 // Equal contribution from multiple scattering in non bending and bending directions
772 clusterWeightsB(iCurrentCluster1, iCurrentCluster2) = clusterWeightsNB(iCurrentCluster1, iCurrentCluster2);
774 // Add contribution from cluster resolution to diagonal element and symmetrize the matrix
775 if (iCurrentCluster1 == iCurrentCluster2) {
777 // In non bending plane
778 clusterWeightsNB(iCurrentCluster1, iCurrentCluster1) += cluster1->GetErrX2();
780 clusterWeightsB(iCurrentCluster1, iCurrentCluster1) += cluster1->GetErrY2();
784 // In non bending plane
785 clusterWeightsNB(iCurrentCluster2, iCurrentCluster1) = clusterWeightsNB(iCurrentCluster1, iCurrentCluster2);
787 clusterWeightsB(iCurrentCluster2, iCurrentCluster1) = clusterWeightsB(iCurrentCluster1, iCurrentCluster2);
797 // Inversion of covariance matrices to get the weights
798 if (clusterWeightsNB.Determinant() != 0 && clusterWeightsB.Determinant() != 0) {
799 clusterWeightsNB.Invert();
800 clusterWeightsB.Invert();
802 AliWarning(" Determinant = 0");
803 clusterWeightsNB.ResizeTo(0,0);
804 clusterWeightsB.ResizeTo(0,0);
805 if(deleteMCSCov) delete mcsCovariances;
809 if(deleteMCSCov) delete mcsCovariances;
815 //__________________________________________________________________________
816 void AliMUONTrack::ComputeMCSCovariances(TMatrixD& mcsCovariances) const
818 /// Compute the multiple scattering covariance matrix
819 /// (assume that track parameters at each cluster are corrects)
820 AliDebug(1,"Enter ComputeMCSCovariances");
822 // Reset the size of the covariance matrix if needed
823 Int_t nClusters = GetNClusters();
824 if (mcsCovariances.GetNrows() != nClusters) mcsCovariances.ResizeTo(nClusters,nClusters);
827 Int_t nChambers = AliMUONConstants::NTrackingCh();
828 AliMUONTrackParam* trackParamAtCluster;
829 AliMUONTrackParam extrapTrackParam;
830 Int_t currentChamber = 0, expectedChamber = 0, size = 0;
831 Double_t *mcsAngle2 = new Double_t[2*nChambers];
832 Double_t *zMCS = new Double_t[2*nChambers];
833 Int_t *indices = new Int_t[2*nClusters];
835 // Compute multiple scattering dispersion angle at each chamber
836 // and save the z position where it is calculated
837 for (Int_t iCluster = 0; iCluster < nClusters; iCluster++) {
838 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster);
840 // look for missing chambers if any
841 currentChamber = trackParamAtCluster->GetClusterPtr()->GetChamberId();
842 while (currentChamber > expectedChamber) {
844 // Save the z position where MCS dispersion is calculated
845 zMCS[size] = AliMUONConstants::DefaultChamberZ(expectedChamber);
847 // Do not take into account MCS in chambers prior the first cluster
850 // Get track parameters at missing chamber z
851 extrapTrackParam = *trackParamAtCluster;
852 AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, zMCS[size]);
854 // Save multiple scattering dispersion angle in missing chamber
855 mcsAngle2[size] = AliMUONTrackExtrap::GetMCSAngle2(extrapTrackParam,AliMUONConstants::ChamberThicknessInX0(),1.);
857 } else mcsAngle2[size] = 0.;
863 // Save z position where MCS dispersion is calculated
864 zMCS[size] = trackParamAtCluster->GetZ();
866 // Save multiple scattering dispersion angle in current chamber
867 mcsAngle2[size] = AliMUONTrackExtrap::GetMCSAngle2(*trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(),1.);
869 // Save indice in zMCS array corresponding to the current cluster
870 indices[iCluster] = size;
872 expectedChamber = currentChamber + 1;
876 // complete array of z if last cluster is on the last but one chamber
877 if (currentChamber != nChambers-1) zMCS[size++] = AliMUONConstants::DefaultChamberZ(nChambers-1);
879 // Compute the covariance matrix
880 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
882 for (Int_t iCluster2 = iCluster1; iCluster2 < nClusters; iCluster2++) {
884 // Initialization to 0 (diagonal plus upper triangular part)
885 mcsCovariances(iCluster1,iCluster2) = 0.;
887 // Compute contribution from multiple scattering in upstream chambers
888 for (Int_t k = 0; k < indices[iCluster1]; k++) {
889 mcsCovariances(iCluster1,iCluster2) += (zMCS[indices[iCluster1]] - zMCS[k]) * (zMCS[indices[iCluster2]] - zMCS[k]) * mcsAngle2[k];
892 // Symetrize the matrix
893 mcsCovariances(iCluster2,iCluster1) = mcsCovariances(iCluster1,iCluster2);
904 //__________________________________________________________________________
905 Int_t AliMUONTrack::ClustersInCommon(AliMUONTrack* track) const
907 /// Returns the number of clusters in common between the current track ("this")
908 /// and the track pointed to by "track".
909 if (!fTrackParamAtCluster || !this->fTrackParamAtCluster) return 0;
910 Int_t clustersInCommon = 0;
911 AliMUONTrackParam *trackParamAtCluster1, *trackParamAtCluster2;
912 // Loop over clusters of first track
913 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->First();
914 while (trackParamAtCluster1) {
915 // Loop over clusters of second track
916 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->First();
917 while (trackParamAtCluster2) {
918 // Increment "clustersInCommon" if both trackParamAtCluster1 & 2 point to the same cluster
919 if ((trackParamAtCluster1->GetClusterPtr()) == (trackParamAtCluster2->GetClusterPtr())) {
923 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->After(trackParamAtCluster2);
924 } // trackParamAtCluster2
925 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->After(trackParamAtCluster1);
926 } // trackParamAtCluster1
927 return clustersInCommon;
930 //__________________________________________________________________________
931 Double_t AliMUONTrack::GetNormalizedChi2() const
933 /// return the chi2 value divided by the number of degrees of freedom (or 1.e10 if ndf < 0)
935 Double_t numberOfDegFree = (2. * GetNClusters() - 5.);
936 if (numberOfDegFree > 0.) return fGlobalChi2 / numberOfDegFree;
937 else return fGlobalChi2; // system is under-constraint
940 //__________________________________________________________________________
941 Bool_t* AliMUONTrack::CompatibleTrack(AliMUONTrack *track, Double_t sigmaCut) const
943 /// for each chamber: return kTRUE (kFALSE) if clusters are compatible (not compatible)
944 AliMUONTrackParam *trackParamAtCluster1, *trackParamAtCluster2;
945 AliMUONVCluster *cluster1, *cluster2;
946 Double_t chi2, dX, dY, dZ;
947 Double_t chi2Max = sigmaCut * sigmaCut;
948 Double_t dZMax = 1.; // 1 cm
950 Bool_t *compatibleCluster = new Bool_t[AliMUONConstants::NTrackingCh()];
951 for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) compatibleCluster[ch] = kFALSE;
953 if (!fTrackParamAtCluster || !this->fTrackParamAtCluster) return compatibleCluster;
955 // Loop over clusters of first track
956 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->First();
957 while (trackParamAtCluster1) {
959 cluster1 = trackParamAtCluster1->GetClusterPtr();
961 // Loop over clusters of second track
962 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->First();
963 while (trackParamAtCluster2) {
965 cluster2 = trackParamAtCluster2->GetClusterPtr();
968 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->After(trackParamAtCluster2);
971 dZ = cluster1->GetZ() - cluster2->GetZ();
972 if (dZ > dZMax) continue;
974 // non bending direction
975 dX = cluster1->GetX() - cluster2->GetX();
976 chi2 = dX * dX / (cluster1->GetErrX2() + cluster2->GetErrX2());
977 if (chi2 > chi2Max) continue;
980 dY = cluster1->GetY() - cluster2->GetY();
981 chi2 = dY * dY / (cluster1->GetErrY2() + cluster2->GetErrY2());
982 if (chi2 > chi2Max) continue;
984 compatibleCluster[cluster1->GetChamberId()] = kTRUE;
988 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->After(trackParamAtCluster1);
991 return compatibleCluster;
994 //__________________________________________________________________________
995 void AliMUONTrack::SetTrackParamAtVertex(const AliMUONTrackParam* trackParam)
997 /// set track parameters at vertex
998 if (trackParam == 0x0) return;
999 if (fTrackParamAtVertex) *fTrackParamAtVertex = *trackParam;
1000 else fTrackParamAtVertex = new AliMUONTrackParam(*trackParam);
1003 //__________________________________________________________________________
1004 void AliMUONTrack::RecursiveDump() const
1006 /// Recursive dump of AliMUONTrack, i.e. with dump of trackParamAtCluster and attached clusters
1007 AliMUONTrackParam *trackParamAtCluster;
1008 AliMUONVCluster *cluster;
1009 cout << "Recursive dump of Track: " << this << endl;
1012 for (Int_t iCluster = 0; iCluster < GetNClusters(); iCluster++) {
1013 trackParamAtCluster = (AliMUONTrackParam*) ((*fTrackParamAtCluster)[iCluster]);
1014 // trackParamAtCluster
1015 cout << "trackParamAtCluster: " << trackParamAtCluster << " (index: " << iCluster << ")" << endl;
1016 trackParamAtCluster->Dump();
1017 cluster = trackParamAtCluster->GetClusterPtr();
1019 cout << "cluster: " << cluster << endl;
1025 //_____________________________________________-
1026 void AliMUONTrack::Print(Option_t*) const
1028 /// Printing Track information
1030 cout << "<AliMUONTrack> No.Clusters=" << setw(2) << GetNClusters() <<
1031 ", Match2Trig=" << setw(1) << GetMatchTrigger() <<
1032 ", LoTrgNum=" << setw(3) << GetLoTrgNum() <<
1033 ", Chi2-tracking-trigger=" << setw(8) << setprecision(5) << GetChi2MatchTrigger();
1034 cout << Form(" HitTriggerPattern %x",fHitsPatternInTrigCh) << endl;
1035 if (fTrackParamAtCluster) fTrackParamAtCluster->First()->Print("FULL");
1038 //__________________________________________________________________________
1039 void AliMUONTrack::SetLocalTrigger(Int_t loCirc, Int_t loStripX, Int_t loStripY, Int_t loDev, Int_t loLpt, Int_t loHpt)
1041 /// pack the local trigger information and store
1043 if (loCirc < 0) return;
1046 fLocalTrigger += loCirc;
1047 fLocalTrigger += loStripX << 8;
1048 fLocalTrigger += loStripY << 13;
1049 fLocalTrigger += loDev << 17;
1050 fLocalTrigger += loLpt << 22;
1051 fLocalTrigger += loHpt << 24;